《數(shù)據(jù)庫開發(fā)過程》word版

1、畢業(yè)設(shè)計外文翻譯英文文獻(xiàn)參考Database Development ProcessBased on information engineering information systems planning database is a source of development projects. These new database development projects is usually in order to meet the strategic needs of organizations, such as improving customer support, improve

2、product and inventory management, or a more accurate sales forecast. However, many more database development project is the bottom-up approach emerging, such as information system user needs specific information to complete their work, thus beginning a project request, and as other information syste

3、ms experts found that organizations need to improve data management and begin new projects. Bottom-up even in the circumstances, to set up an enterprise data model is also necessary to understand the existing database can provide the necessary data, otherwise, the new database, data entities and att

4、ributes can be added to the current data resources to the organization.Both the strategic needs or operational information needs of each database development projects normally concentrated in a database. Some projects only concentrated in the database definition, design and implementation of a datab

5、ase, as a follow-up to the basis of the development of information systems. However, in most cases, the database and associated information processing function as a complete information systems development project was part of the development. 2.1 System Development Life Cycle Guide management inform

6、ation system development projects is the traditional process of system development life cycle (SDLC). System development life cycle is an organization of the database designers and programmers information system composed of the Panel of Experts detailed description, development, maintenance and repl

7、acement of the entire information system steps. This process is because Waterfall than for every step into the adjacent the next step, that is, the information system is a specification developed by a piece of land, every piece of the output is under an input. However shown in the figure, these step

8、s are not purely linear, each of the steps overlap in time (and thus can manage parallel steps), but when the need to reconsider previous decisions, but also to roll back some steps ahead. (And therefore water can be put back in the waterfall!) The system development life cycle including each stage

9、and database development-related activities, therefore, the question of database management systems throughout the entire development process. In Figure 5 we repeat of the system development life cycle stage of the seven, and outlines the common database at each stage of development activities. Plea

10、se note that the systems development life cycle stages and database development steps exists between the relationship between the concept of modeling data in both systems development life cycle stages between.1.Enterprise Modeling Database development process from the enterprise modeling (system dev

11、elopment life cycle stage of the project feasibility studies, and to choose a part)Organizations set the scope and general database content. Enterprise modeling in information systems planning and other activities, these activities determine which part of information systems need to change and stren

12、gthen the entire organization and outlines the scope of data. In this step, check the current database and information systems, development of the project as the main areas of the nature of the business, with a very general description of each term in the development of information systems when need

13、ed data. Each item only when it achieved the expected goals of organizations can be when the next step.2.Conceptual Data Modeling One has already begun on the Information System project, the concept of data modeling phase of the information systems needs of all the data. It is divided into two stage

14、s. First, it began the project in the planning stage. At the same time outlining the establishment of other documents to the existing database without considering the circumstances specific development projects in the scope of the required data. This category only includes high-level data (entities)

15、, and main contact. Then in the system development life-cycle analysis stage must have a management information system set the entire organization Details of the data model definition of all data attributes, listing all data types that all data inter-entity business linkages, defining description of

16、 the full data integrity rules. In the analysis phase, but also the concept of inspection data model (also called the concept behind the model) and the goal of information systems used to explain other aspects of the model of consistency categories, such as processing steps, rules and data processin

17、g time of timing. However, even if the concept is such detailed data model is only preliminary, because follow-up information system life cycle activities in the design of services, statements, display and inquiries may find that missing element or mistakes. Therefore, the concept of data often said

18、 that modeling is a top-down manner, its areas of operation from the general understanding of the driver, rather than the specific information processing activities by the driver. 3. Logical Database Design Logical database design from two perspectives database development. First, the concept of dat

19、a model transform into relational database theory based on the criteria that means - between. Then, as the design of information systems, every computer procedures (including procedures for the input and output format), database support services, statements, and inquiries revealed that a detailed ex

20、amination. In this so-called Bottom-up analysis, accurate verification of the need to maintain the database and the data in each affairs, statements and so on the needs of those in the nature of the data. For each separate statements, services, and so on the analysis must take into account a specifi

21、c, limited but complete database view. When statements, services, and other analysis might be necessary to change the concept of data model. Especially in large-scale projects, the different analytical systems development staff and the team can work independently in different procedures or in a cent

22、ralized, the details of their work until all the logic design stage may be displayed. In these circumstances, logic database design stage must be the original concept of data model and user view these independent or merged into a comprehensive design. In logic design information systems also identif

23、y additional information processing needs of these new demands at this time must be integrated into the logic of earlier identified in the database design.Logical database design is based on the final step for the formation of good data specifications and determine the rules, the combination, the da

24、ta after consultation specifications or converted into basic atomic element. Most of todays database, these rules from the relational database theory and the process known as standardization, #. This step is the result of management of these data have not cited any database management system for a c

25、omplete description of the database map. Logical database design completed, we began to identify in detail the logic of the computer program and maintenance, the report contents of the database for inquiries. 4. Physical database design and definitionPhysical database design and definition phase dec

26、isions computer memory (usually disk) database in the organization, definition of According to the library management system for physical structure, the procedures outlined processing services, produce the desired management information and decision support statements. The objective of this stage is

27、 to design an effective and safe management of all data-processing database, the physical database design to closely integrate the information systems of other physical aspects of the design, including procedures, computer hardware, operating systems and data communications networks. 5. Database Imp

28、lementation The database prepared by the realization stage, testing and installation procedures for handling databases. Designers can use the standard programming language (such as COBOL, C or Visual Basic), the dedicated database processing languages (such as SQL), or the process of the non-exclusi

29、ve language programming in order to produce a statement of the fixed format, the result will be displayed, and may also include charts. In achieving stage, but also the completion of all the database files, training users for information systems (database) user setup program. The final step is to us

30、e existing sources of information (documents legacy applications and databases and now needs new data) loading data. Loading data is often the first step in data from existing files and databases to an intermediate format (such as binary or text files) and then to turn intermediate loading data to a

31、 new database. Finally, running databases and related applications for the actual user maintenance and retrieval of data. In operation, the regular backup database and the database when damaged or affected resume database.6. Database maintenance During the database in the progressive development of

32、database maintenance. In this step, in order to meet changing business conditions, in order to correct the erroneous database design, database applications or processing speed increase, delete or change the structure of the database. When a procedure or failure of the computer database affect or dam

33、age the database may also be reconstruction. This step usually is the longest in the database development process step, as it continued to databases and related applications throughout the life cycle, the development of each database can be seen as a brief database development process and data model

34、ing concepts arise, logical and physical database design and database to achieve dealing with the changes. 2.2 Information System developed by other means System Development Life Cycle minor changes in law or its variant of the often used to guide information systems and database development. Inform

35、ation System is a life-cycle methodology, it is highly structured approach, which includes many checks and balances to ensure that every step of produce accurate results, and new or alternative information system and it must communications or data definitions consistent existing system needs consist

36、ency. System development life cycle because of the regular need to have a working system for a long time been criticized because only work in the system until the end of the whole process generated. More and more organizations now use rapid application development method, it is a includes analysis,

37、design and implementation of steps to repeat the rapid iterative process until convergence to users the system so far. Rapid Application Development Act required the database has been in existence, and enhance system is mainly to the application of data retrieval application, but not to those who ge

38、nerate and modify database applications. The most widely used method of rapid application development is one of the prototype. The prototype system is a method of iterative development process, analysts and users through close co-operation, continuing to revise the system will eventually convert all

39、 the needs of a working system. In this diagram we contains notes, briefly describes each stage of the prototype of the database development activities. Normally, when information systems problems were identified, tried only a rough concept of data modeling. In the development of the initial prototy

40、pe, the design of the user wants to display and statements, and that any new database needs and define a term prototype database. This is usually a new database, copy the part of the existing system, but might also added some new content. When the need for new content, these elements are usually from external data sources, such as market research data, the general economic indicators or industry standards. When a prototype of a new version to repeat the achievement and maintenance of database activities. Usually only a minimum level of security and integrity co